This invention relates to a shield connector, and more particularly to a shield connector in which the ability of contact between a shielding terminal and a connector housing is enhanced so as to positively achieve the shielding in a stable manner.
In a related shield connector, a connector housing which is made of an electrically-conductive material (such as aluminum) is used, and a shielding terminal, connected to an electrically-conductive shielding member, is disposed to be electrically connected to the connector housing, thereby shielding a connector portion. FIGS. 9 to 11 show a well-known shield connector. FIG. 9 is a perspective view of the shield connector, showing its appearance, FIG. 10 is a vertical cross-sectional view taken along the line X—X of FIG. 9, and FIG. 11 is an enlarged view of a portion encircled by a circle X1 of FIG. 10.
As shown in FIGS. 9 to 11, the shield connector 1 includes a connector housing 9, and this connector housing 9 includes a connector housing base 3 made of an electrically-conductive material such as aluminum, and a housing 5 made of an insulative material such as a synthetic resin. The connector housing base 3 and the housing 5 are fixed to each other by bolts 7.
A shielding terminal 11 is formed of a thin plate or sheet made of an electrically-conductive material such as copper, and this shielding terminal 11 includes a conducting plate portion 11a having plate shape, and shielding shells 11b of a generally cylindrical shape formed on and projecting upwardly from the conducting plate portion 11a. The conducting plate portion 11a is held between the connector housing base 3 and the housing 5. A collar 21 is fitted in each of bolt holes 5b formed in the housing 5, and the bolts 7 are passed respectively through the collars 21, and fasten the connector housing base 3 and the housing 5 together. The shielding shells 11b are fitted respectively in connector chambers 5a of the housing 5.
Ring-shaped convex contact portions 11c of a generally inverted V-shaped cross-section are formed on the conducting plate portion 11a, and are disposed respectively around through holes (each for the passage of the bolt 7) formed through the conducting plate portion 11a (see FIG. 11). An end surface of each collar 21 abuts against the corresponding convex contact portion 11c. A plurality of resilient contact piece portions 11d are formed at one end portion (upper end portion in FIG. 10) of the shielding shell 11b, fitted in the connector chamber 5a, which is to be disposed close to a mating connector, the resilient contact piece portions 11d being formed by stamping relevant portions of the one end portion and then by bending these portions inwardly into a curved shape.
An inner housing 15 receives and holds shielded wires (or cables) 13 each having a conductor (also called “core wire”) 13a exposed within the inner housing 15. The inner housing 15 is fitted in those portions of the shielding shells 11b disposed close to the conducting plate portion 11a. The inner housing 15 passes through through holes 3a in the connector housing base 3, and is fitted in the connector chambers 5a of the housing 5. Male pin terminals 22 are electrically connected at their one ends respectively to the conductors 3a of the shielded wires 3, and are disposed coaxially with the shielding shells 11b, respectively.
As shown in FIG. 11, the conducting plate portion 11a of the shielding terminal 11 is held between the connector housing base 3 and the collars 21 (and also the housing 5), and when the conducting plate portion 11a is fixed to the housing 5 by the bolts 7, the convex contact portions 11c are pressed by the collars 21, respectively, so that the conducting plate portion 11a is held in contact with a surface 3b of the connector housing base 3. As a result, the shielding terminal 11 is electrically connected to the connector housing base 3, thereby achieving the shielding.
In the above related shield connector 1, the thin-plate shaped conducting plate portion 11a of the shielding terminal 11 is held in contact with the surface 3b of the connector housing base 3 by tightening the bolts 7, and therefore tightening loads, applied respectively from the bolts 7, concentrate on those portions of the conducting plate portion 11a positioned near respectively to the bolts 7. Therefore, only those portions of the conducting plate portion 11a, positioned respectively around the bolts 7, are held in contact with the connector housing base 3, and there is a possibility that at the other regions remote from the bolts 7, a gap is formed between the surface 3b of the connector housing base 3 and the conducting plate portion 11a of the shielding terminal 11. Therefore, the effective contact area that has a small electrical contact resistance is limited to the vicinities of the bolts 7, and there is a possibility that the effective contact area is inadequate, so that the shielding performance is insufficient. Even if the bolts 7 are directly passed respectively through the bolt holes 5b in the housing 5 without the use of the collars 21, and the conducting plate portion 11a is pressed against the connector housing base 3 through the housing 5, there is a possibility that a gap is formed between the surface 3b of the connector housing base 3 and the conducting plate portion 11a at the regions remote from the bolts 7, since the synthetic resin-made housing 5 has a relatively low mechanical strength. Thus, as is the case where the collars 21 are used, there is still the possibility that the sufficient effective contact area is not secured.